普洱茶中一株产纤维素酶黑曲霉的分离及鉴定

Isolation and identification of a cellulase-producing strain Aspergillus niger from Pu‑erh tea

中文关键词:  黑曲霉  纤维素酶  普洱茶  分离鉴定

英文关键词:Aspergillus niger  cellulase  Pu‑erh tea  isolation and identification

中文摘要:

      目的 分离、鉴定普洱茶中一株产纤维素酶的黑曲霉(Aspergillus niger)菌株。方法 对从普洱茶中得到霉菌菌株进行富集培养和纯化分离, 后经过刚果红染色法初筛以及滤纸酶活力法复筛, 得到具有较强产纤维素酶能力和较高纤维素酶活力的目的菌株, 并测定其酶活力。结果 从普洱茶中分离得到24株霉菌菌株, 经初步筛选得到7株具有较强产纤维素酶能力的菌株, 水解圈直径与菌落直径最大比值达1.76, 通过测定滤纸酶活力复筛得到一株具有较高纤维素酶活力的菌株, 在发酵第9 d时其纤维素酶活力达到16.58 U/mL。结合菌落和显微形态鉴定以及菌株ITS基因序列分析确定该菌株为黑曲霉, 菌株命名为XO-18。结论 本研究筛选获得产纤维素黑曲霉XO-18, 该菌株产酶活力高, 具有开发成食品工业发酵用菌, 满足食品工业需求的潜力。

英文摘要:

      Objective To isolate and identify a cellulase-producing Aspergillus niger strains from Pu-erh tea. Methods Mold strains were isolated and purified from Pu-erh tea after enrichment cultivation, then the target strains were screened by Congo red staining and secondary screening using filter paper enzyme activity method, then obtained the target fungal strains with strong cellulose-degrading ability and high cellulase activity, and measured their enzyme activity. Results Totally 24 mold strains were isolated from Pu-erh tea, and 7 of them showed strong enzyme production ability in preliminary screening. The maximum ratio of hydrolysis ring diameter to colony diameter reached 1.76. The strain with highest cellulase activity was verified to be 16.58 U/mL on the 9th days of fermentation when measured by filter paper assay method of cellulase enzymes. Combined microscopy morphology observation with ITS gene sequence analysis, this strain was identified to be Aspergillus niger, and named as XO-18. Conclusion In this study, the strain of cellulose-producing Aspergillus niger XO-18 is screened and obtained. This strain has high enzyme production activity, and has the potential to be developed into fermentation bacteria for food industry to satisfy the needs of food industry.